Structural brain abnormalities in psychopaths-a review.

The biological basis of psychopathy has not yet been fully elucidated. Few studies deal with structural neuroimaging in psychopaths. The aim of this article is to review these studies in order to contribute to our understanding of the biological basis of psychopathy. Data in the literature report a reduction in prefrontal gray matter volume, gray matter loss in the right superior temporal gyrus, amygdala volume loss, a decrease in posterior hippocampal volume, an exaggerated structural hippocampal asymmetry, and an increase in callosal white matter volume in psychopathic individuals. These findings suggest that psychopathy is associated with brain abnormalities in a prefrontal-temporo-limbic circuit-i.e. regions that are involved, among others, in emotional and learning processes. Additionally, data indicate that psychopathic individuals cannot be seen as a homogeneous group. The associations between structural changes and psychopathic characteristics do not enable causal conclusions to be drawn, but point rather to the important role of biological brain abnormalities in psychopathy. To gain a comprehensive understanding of this, psychopathy must be viewed as a multifactorial process involving neurobiological, genetic, epidemiological and sociobiographical factors.